Normally, a metal sleeve or the like is installed prior to the pouring of concrete which is then removed when the concrete has set. Alternatively, the concrete has to be drilled in order to form the hole through which various pipes, conduits and the like are required to pass. Such conduits may include dryer vents, bathroom vents, air intakes, venting openings, water, gas and electrical conduits and the like.
The present methods suffer from several disadvantages. Obviously when concrete has to be drilled after it has set, considerable time and effort is required. Furthermore, it is difficult to form an aperture through a concrete wall which is of the correct dimension and which is provided with relatively smooth sides. This means that the wall has to be patched and filled after the conduit or the like has been extended through the concrete wall or floor.
The metal sleeve also suffers from several disadvantages inasmuch as it is usually relatively thin walled which wall is easily distorted during the pouring of the concrete. Furthermore, when the walls and/or floor are poured, it is not always known exactly where such vents are required and furthermore, if they are not required immediately, they have to be temporarily filled or sealed in order to preserve the integrity of the wall or floor.